The potential model treatment of the scattering of electrons by atoms and the existence of negative ions

Abstract

The low energy scattering of electrons by different neutral atoms has been treated by assuming that the atomic wave functions remain unchanged even at the presence of the scattered particle and by neglecting the exchange between the scattered electron and the bound electrons. The potential term in the differential equation of the scattered particle is exactly the atomic potential of the neutral atom and is approximated by analytical expressions, yielding the potential scattering equation. The variational treatments of Hulthén, Kohn and a related one suggested by Malik, are applied to solve this equation for a Hartree atom with l=0. The scattering by He, C and N is treated explicitly and the results of He indicate that in this way one may get some good result without going into the great complexity of the many body problem. It is further pointed out that the study of scattering by neutral atoms near zero energy under this model may serve as a possible mean to investigate the existence of different negative ions and their number of bound states. It seems from this point of view that He^-, C^- and N^- for this model may exist and have one bound s-state.